# 检查用户名
current_users = ['Admin', 'Tom', 'Jerry', 'Jack', 'James']
current_users_lower = [user.lower() for user in current_users]
new_users = ['Admin', 'lucy', 'jerry', 'jack', 'jimmy']
for new_user in new_users:
    if new_user.lower() in current_users_lower:
        print(f"{new_user},用户名已被占用，请重新输入")
    else:
        print(f"{new_user},用户名可以使用")